Help! Bone Heat Weighting: failed to find solution for one or more bones
Thanks to  batFINGER! Im going to post the solution in photos, maybe helps someone who was a little lost like me :))
Select only the object and choose edit mode, there click in select, and then select all by trait. There select non manifold. 
In the box that apears in the bottom, deselect Vertices
Still in edit mode go to mesh, select merge and click in By Distance

Now try parenting in object mode

And for me it worked :)